At the outset, the terms "inverter", "converter" and "intrinsic DC load means" shall be defined insofar as usage in this disclosure is concerned. "Inverter" shall mean a device, circuit or system that delivers ac power when energized from a source of dc power i.e., it is the opposite of rectification. "Converter" shall mean a circuit or system that both receives and provides dc power in which ac is generated as an intermediate process in the flow of energy. The term "intrinsic DC load means" shall mean a DC load means which functions only in response to DC power input, i.e., it does not require and should not tolerate the inherent inefficiency and complexity of a converter in order to function properly.
My prior U.S. Pat. No. 5,500,561 is directed to A CUSTOMER SIDE POWER MANAGEMENT SYSTEM AND METHOD and discloses several embodiments wherein substantial relaxation is achieved in the requirement that an electric or public utility maintain a generating capacity far exceeding the anticipated maximum demand for electricity. Generally speaking, my prior patent is directed to systems wherein a direct current power supply means, such as, for example, a DC power source, in the form of storage battery means is included in the power management system and operates to alleviate excessive power demands on the electric utility.
Briefly stated, the problem addressed in my prior applications is, at its heart, based upon the fact that power demands placed upon the electric utilities by consumers fluctuate enormously dependent upon the time of day, the day of the week, the season of the year and/or any other factor which may affect demand, including the type of consumer. So-called uninterruptible power supplies have been proposed but are generally inadequate to alleviate the problem efficiently. Such a system is exemplified by the Lavin et al U.S. Pat. No. 5,289,045 of Feb. 22, 1994 and attention is called to the references cited as prior art against my aforesaid prior applications.
This application relates to electrical distribution generally and in particular to electrical distribution as it applies particularly to dwellings for example, wherein it is well known that electrical energy is distributed from a public or electric utility in AC form, normally in split-phase having the meaning that two 120 V AC phases of the utility are brought into a building so as to be available as two 120 V AC circuits and a 240 V AC circuit. Such a three-wire system involves the use of two line power conductors and a neutral wire conductor supplied by the utility. These conductors, according to usual practice, are brought into the customer's distribution box and connected therein to two line power busses through suitable circuit breaker means, such as, for example, a current responsive circuit interrupter, and directly to a neutral buss housed within the box. The box also houses a ground buss which, according to normal practice, is provided with a wire connection extending externally of the box and into electrical connection with an earthing pole which establishes earth potential at the ground buss.
This application is directed to the problem of efficiently using and/or utilizing electrical power and to the method thereof--more specifically, of efficiently utilizing DC power at the site of interest by establishing a dual voltage capability at such site. Further, this application is directed to the problem where multiple earth grounds are established within an electrical distribution system, causing undesirable DC current paths.
An object of this invention is to permit two different power supply systems, one DC and the other AC, to reside on common building wiring as found in the United States and elsewhere in the world.
Another object of this invention is to provide a compatible power wiring system that allows both DC power operation and AC power operation to coexist, without modification to the power wiring system, from common building wiring power outlets. This compatibility allows, for example, appliances which operate on low voltage 24 V DC, especially those which now do or in the future will function as "intrinsic DC devices", and conventional 120 V AC appliances to be used within the same building space and with existing cabling or wiring.
Another object of this invention is to introduce the concept of ganged circuit breaker means in power wiring systems.
Still another object of this invention is the provision of dual voltage capability with ganged circuit breaker means functioning to interrupt not only both the "high" and "low" sides of AC voltage circuitry but DC circuitry as well.
Stated otherwise, the preceding object may utilize one circuit breaker means in an AC path and a second circuit breaker means in a DC current path as well.
Still another object of this invention is to provide an intrinsic DC load circuit means that embodies looping of the wiring through one circuit breaker means connecting to one side of the DC power source and through a second circuit breaker means to the other side of the DC power source.
A further object of this invention is to provide apparatus that requires only a simple input connection after the electric distribution box of living quarters or of a dwelling (either mobile or not) such that it will function in a variety of different ways which permit stand alone function with DC energy input from a plurality of DC power source means i.e., from a generator means, photo-voltaic means, wind turbine means, etc.
A further object of the invention is to provide the combination of filter capacitor means and storage battery means disposed in electrical parallel, the filter capacitor means functioning as a limited AC path to ground, sized, in capacitance to assure a low impedance path to ground at 60 Hz, the storage battery means functioning to conduct current in opposite directions, consistent with the requirements for AC conduction to ground. That is, the storage battery means and its associated DC power supply provide both a DC isolation path to ground and an AC continuity path to ground whereas the filter capacitor means supplies a limited AC path to ground.
A further object of this invention is to provide a system in conformity with the preceding object wherein the filter capacitor means is hard wired within the electrical distribution box and the storage battery means is housed within the module unit of this invention.
Another object of the invention is to provide the combination of an electrical distribution box housing neutral buss means, power buss means, ground buss means and filter capacitor means, the latter being of limited capacitance and little bulk so as to provide a limited AC path to ground, and a modular power system module unit which houses storage battery means of substantial capacitance and large bulk compared with said filter capacitor means so as to conduct current in opposite directions to provide for AC conduction to ground.
Another object of the invention is to provide a practical approach to the application of building-side DC power for intrinsic DC devices or loads. As noted above, by intrinsic DC devices or loads is meant DC devices which are intended to be operated only on DC. That is, although an intrinsic DC device can operate when supplied with any DC power, it is not intended that an "intrinsic DC device" be operated by converted DC because of the inevitable loss of efficiency when ac is generated as the intermediate process in the flow of energy.
It is a further object of this invention to minimize a customer's peak power demands by using a storage battery means for peak clipping and valley filling purposes.
Another important object of this invention is to provide a modular unit in which the modular unit comprises storage battery means for providing a battery equivalent capacitance which is very large in capacitance and bulk in combination with voltage regulator means (not a converter) for controlling the charge level of the storage battery means.
Another object of this invention is to provide a system in accord with the preceding object in combination with intrinsic DC load means for utilizing the storage capacity of the storage battery means.
Another object of this invention is to provide a modular system using a rechargeable storage battery means as part of a critical conversion circuit for filtering (minimizing the AC ripple inherent with rectified AC) and voltage regulation (in the absence of conversion, i.e., not a converter) to protect the storage battery means from damage by overcharging or undercharging (minimizing the DC voltage variation due to load and line supply variations) and in which the storage battery means supplies power to an intrinsic DC load means.
Still another object of the invention is to provide the combination of an electrical distribution box housing neutral buss means, power buss means, ground buss means and filter capacitor means, the latter being of limited capacitance and little bulk so as to provide a limited AC path to ground and be DC blocking, and a modular power system module unit which houses storage battery means of substantial capacitance and large bulk compared with said filter capacitor means, and intrinsic DC load means for drawing upon the storage capacity of said storage battery means.
A further object of this invention involves the battery equivalent capacitance of said storage battery means being very large, consistent with an ideal AC path to ground and the capacitance of said filter capacitor means being very small, consistent with a limited AC path to ground but large enough to pass sufficient current to keep the worse case fault currents well below any shock hazards and to allow sufficient current flow to trip relevant circuit breakers in the event of a short circuit.
It is an object of this invention to provide an arrangement in accord with the preceding object in combination with converter means in which high frequency AC is generated as an intermediate process in the flow of energy and in which special capacitor means is provided for absorbing voltage spikes of said high frequency AC.
It is a feature of the invention is to provide the combination of an electrical distribution box housing a neutral buss, a power buss, a ground buss and a DC isolation capacitor, the DC isolation capacitor being of sufficient capacitance and little bulk, so as to provide an AC path through the neutral conducting circuit and be DC blocking.